text: // SPDX-License-Identifier: GPL-2.0
  #include "builtin.h"
  #include "perf.h"
  
  #include "util/evlist.h"
  #include "util/evsel.h"
  #include "util/util.h"
  #include "util/config.h"
  #include "util/symbol.h"
  #include "util/thread.h"
  #include "util/header.h"
  #include "util/session.h"
  #include "util/tool.h"
  #include "util/callchain.h"
  #include "util/time-utils.h"
  
  #include <subcmd/parse-options.h>
  #include "util/trace-event.h"
  #include "util/data.h"
  #include "util/cpumap.h"
  
  #include "util/debug.h"
  
  #include <linux/kernel.h>
  #include <linux/rbtree.h>
  #include <linux/string.h>
  #include <errno.h>
  #include <inttypes.h>
  #include <locale.h>
  #include <regex.h>
  
  #include "sane_ctype.h"
  
  static int	kmem_slab;
  static int	kmem_page;
  
  static long	kmem_page_size;
  static enum {
  	KMEM_SLAB,
  	KMEM_PAGE,
  } kmem_default = KMEM_SLAB;  /* for backward compatibility */
  
  struct alloc_stat;
  typedef int (*sort_fn_t)(void *, void *);
  
  static int			alloc_flag;
  static int			caller_flag;
  
  static int			alloc_lines = -1;
  static int			caller_lines = -1;
  
  static bool			raw_ip;
  
  struct alloc_stat {
  	u64	call_site;
  	u64	ptr;
  	u64	bytes_req;
  	u64	bytes_alloc;
  	u64	last_alloc;
  	u32	hit;
  	u32	pingpong;
  
  	short	alloc_cpu;
  
  	struct rb_node node;
  };
  
  static struct rb_root root_alloc_stat;
  static struct rb_root root_alloc_sorted;
  static struct rb_root root_caller_stat;
  static struct rb_root root_caller_sorted;
  
  static unsigned long total_requested, total_allocated, total_freed;
  static unsigned long nr_allocs, nr_cross_allocs;
  
  /* filters for controlling start and stop of time of analysis */
  static struct perf_time_interval ptime;
  const char *time_str;
  
  static int insert_alloc_stat(unsigned long call_site, unsigned long ptr,
  			     int bytes_req, int bytes_alloc, int cpu)
  {
  	struct rb_node **node = &root_alloc_stat.rb_node;
  	struct rb_node *parent = NULL;
  	struct alloc_stat *data = NULL;
  
  	while (*node) {
  		parent = *node;
  		data = rb_entry(*node, struct alloc_stat, node);
  
  		if (ptr > data->ptr)
  			node = &(*node)->rb_right;
  		else if (ptr < data->ptr)
  			node = &(*node)->rb_left;
  		else
  			break;
  	}
  
  	if (data && data->ptr == ptr) {
  		data->hit++;
  		data->bytes_req += bytes_req;
  		data->bytes_alloc += bytes_alloc;
  	} else {
  		data = malloc(sizeof(*data));
  		if (!data) {
  			pr_err("%s: malloc failed\n", __func__);
  			return -1;
  		}
  		data->ptr = ptr;
  		data->pingpong = 0;
  		data->hit = 1;
  		data->bytes_req = bytes_req;
  		data->bytes_alloc = bytes_alloc;
  
  		rb_link_node(&data->node, parent, node);
  		rb_insert_color(&data->node, &root_alloc_stat);
  	}
  	data->call_site = call_site;
  	data->alloc_cpu = cpu;
  	data->last_alloc = bytes_alloc;
  
  	return 0;
  }
  
  static int insert_caller_stat(unsigned long call_site,
  			      int bytes_req, int bytes_alloc)
  {
  	struct rb_node **node = &root_caller_stat.rb_node;
  	struct rb_node *parent = NULL;
  	struct alloc_stat *data = NULL;
  
  	while (*node) {
  		parent = *node;
  		data = rb_entry(*node, struct alloc_stat, node);
  
  		if (call_site > data->call_site)
  			node = &(*node)->rb_right;
  		else if (call_site < data->call_site)
  			node = &(*node)->rb_left;
  		else
  			break;
  	}
  
  	if (data && data->call_site == call_site) {
  		data->hit++;
  		data->bytes_req += bytes_req;
  		data->bytes_alloc += bytes_alloc;
  	} else {
  		data = malloc(sizeof(*data));
  		if (!data) {
  			pr_err("%s: malloc failed\n", __func__);
  			return -1;
  		}
  		data->call_site = call_site;
  		data->pingpong = 0;
  		data->hit = 1;
  		data->bytes_req = bytes_req;
  		data->bytes_alloc = bytes_alloc;
  
  		rb_link_node(&data->node, parent, node);
  		rb_insert_color(&data->node, &root_caller_stat);
  	}
  
  	return 0;
  }
  
  static int perf_evsel__process_alloc_event(struct perf_evsel *evsel,
  					   struct perf_sample *sample)
  {
  	unsigned long ptr = perf_evsel__intval(evsel, sample, "ptr"),
  		      call_site = perf_evsel__intval(evsel, sample, "call_site");
  	int bytes_req = perf_evsel__intval(evsel, sample, "bytes_req"),
  	    bytes_alloc = perf_evsel__intval(evsel, sample, "bytes_alloc");
  
  	if (insert_alloc_stat(call_site, ptr, bytes_req, bytes_alloc, sample->cpu) ||
  	    insert_caller_stat(call_site, bytes_req, bytes_alloc))
  		return -1;
  
  	total_requested += bytes_req;
  	total_allocated += bytes_alloc;
  
  	nr_allocs++;
  	return 0;
  }
  
  static int perf_evsel__process_alloc_node_event(struct perf_evsel *evsel,
  						struct perf_sample *sample)
  {
  	int ret = perf_evsel__process_alloc_event(evsel, sample);
  
  	if (!ret) {
  		int node1 = cpu__get_node(sample->cpu),
  		    node2 = perf_evsel__intval(evsel, sample, "node");
  
  		if (node1 != node2)
  			nr_cross_allocs++;
  	}
  
  	return ret;
  }
  
  static int ptr_cmp(void *, void *);
  static int slab_callsite_cmp(void *, void *);
  
  static struct alloc_stat *search_alloc_stat(unsigned long ptr,
  					    unsigned long call_site,
  					    struct rb_root *root,
  					    sort_fn_t sort_fn)
  {
  	struct rb_node *node = root->rb_node;
  	struct alloc_stat key = { .ptr = ptr, .call_site = call_site };
  
  	while (node) {
  		struct alloc_stat *data;
  		int cmp;
  
  		data = rb_entry(node, struct alloc_stat, node);
  
  		cmp = sort_fn(&key, data);
  		if (cmp < 0)
  			node = node->rb_left;
  		else if (cmp > 0)
  			node = node->rb_right;
  		else
  			return data;
  	}
  	return NULL;
  }
  
  static int perf_evsel__process_free_event(struct perf_evsel *evsel,
  					  struct perf_sample *sample)
  {
  	unsigned long ptr = perf_evsel__intval(evsel, sample, "ptr");
  	struct alloc_stat *s_alloc, *s_caller;
  
  	s_alloc = search_alloc_stat(ptr, 0, &root_alloc_stat, ptr_cmp);
  	if (!s_alloc)
  		return 0;
  
  	total_freed += s_alloc->last_alloc;
  
  	if ((short)sample->cpu != s_alloc->alloc_cpu) {
  		s_alloc->pingpong++;
  
  		s_caller = search_alloc_stat(0, s_alloc->call_site,
  					     &root_caller_stat,
  					     slab_callsite_cmp);
  		if (!s_caller)
  			return -1;
  		s_caller->pingpong++;
  	}
  	s_alloc->alloc_cpu = -1;
  
  	return 0;
  }
  
  static u64 total_page_alloc_bytes;
  static u64 total_page_free_bytes;
  static u64 total_page_nomatch_bytes;
  static u64 total_page_fail_bytes;
  static unsigned long nr_page_allocs;
  static unsigned long nr_page_frees;
  static unsigned long nr_page_fails;
  static unsigned long nr_page_nomatch;
  
  static bool use_pfn;
  static bool live_page;
  static struct perf_session *kmem_session;
  
  #define MAX_MIGRATE_TYPES  6
  #define MAX_PAGE_ORDER     11
  
  static int order_stats[MAX_PAGE_ORDER][MAX_MIGRATE_TYPES];
  
  struct page_stat {
  	struct rb_node 	node;
  	u64 		page;
  	u64 		callsite;
  	int 		order;
  	unsigned 	gfp_flags;
  	unsigned 	migrate_type;
  	u64		alloc_bytes;
  	u64 		free_bytes;
  	int 		nr_alloc;
  	int 		nr_free;
  };
  
  static struct rb_root page_live_tree;
  static struct rb_root page_alloc_tree;
  static struct rb_root page_alloc_sorted;
  static struct rb_root page_caller_tree;
  static struct rb_root page_caller_sorted;
  
  struct alloc_func {
  	u64 start;
  	u64 end;
  	char *name;
  };
  
  static int nr_alloc_funcs;
  static struct alloc_func *alloc_func_list;
  
  static int funcmp(const void *a, const void *b)
  {
  	const struct alloc_func *fa = a;
  	const struct alloc_func *fb = b;
  
  	if (fa->start > fb->start)
  		return 1;
  	else
  		return -1;
  }
  
  static int callcmp(const void *a, const void *b)
  {
  	const struct alloc_func *fa = a;
  	const struct alloc_func *fb = b;
  
  	if (fb->start <= fa->start && fa->end < fb->end)
  		return 0;
  
  	if (fa->start > fb->start)
  		return 1;
  	else
  		return -1;
  }
  
  static int build_alloc_func_list(void)
  {
  	int ret;
  	struct map *kernel_map;
  	struct symbol *sym;
  	struct rb_node *node;
  	struct alloc_func *func;
  	struct machine *machine = &kmem_session->machines.host;
  	regex_t alloc_func_regex;
  	const char pattern[] = "^_?_?(alloc|get_free|get_zeroed)_pages?";
  
  	ret = regcomp(&alloc_func_regex, pattern, REG_EXTENDED);
  	if (ret) {
  		char err[BUFSIZ];
  
  		regerror(ret, &alloc_func_regex, err, sizeof(err));
  		pr_err("Invalid regex: %s\n%s", pattern, err);
  		return -EINVAL;
  	}
  
  	kernel_map = machine__kernel_map(machine);
  	if (map__load(kernel_map) < 0) {
  		pr_err("cannot load kernel map\n");
  		return -ENOENT;
  	}
  
  	map__for_each_symbol(kernel_map, sym, node) {
  		if (regexec(&alloc_func_regex, sym->name, 0, NULL, 0))
  			continue;
  
  		func = realloc(alloc_func_list,
  			       (nr_alloc_funcs + 1) * sizeof(*func));
  		if (func == NULL)
  			return -ENOMEM;
  
  		pr_debug("alloc func: %s\n", sym->name);
  		func[nr_alloc_funcs].start = sym->start;
  		func[nr_alloc_funcs].end   = sym->end;
  		func[nr_alloc_funcs].name  = sym->name;
  
  		alloc_func_list = func;
  		nr_alloc_funcs++;
  	}
  
  	qsort(alloc_func_list, nr_alloc_funcs, sizeof(*func), funcmp);
  
  	regfree(&alloc_func_regex);
  	return 0;
  }
  
  /*
   * Find first non-memory allocation function from callchain.
   * The allocation functions are in the 'alloc_func_list'.
   */
  static u64 find_callsite(struct perf_evsel *evsel, struct perf_sample *sample)
  {
  	struct addr_location al;
  	struct machine *machine = &kmem_session->machines.host;
  	struct callchain_cursor_node *node;
  
  	if (alloc_func_list == NULL) {
  		if (build_alloc_func_list() < 0)
  			goto out;
  	}
  
  	al.thread = machine__findnew_thread(machine, sample->pid, sample->tid);
  	sample__resolve_callchain(sample, &callchain_cursor, NULL, evsel, &al, 16);
  
  	callchain_cursor_commit(&callchain_cursor);
  	while (true) {
  		struct alloc_func key, *caller;
  		u64 addr;
  
  		node = callchain_cursor_current(&callchain_cursor);
  		if (node == NULL)
  			break;
  
  		key.start = key.end = node->ip;
  		caller = bsearch(&key, alloc_func_list, nr_alloc_funcs,
  				 sizeof(key), callcmp);
  		if (!caller) {
  			/* found */
  			if (node->map)
  				addr = map__unmap_ip(node->map, node->ip);
  			else
  				addr = node->ip;
  
  			return addr;
  		} else
  			pr_debug3("skipping alloc function: %s\n", caller->name);
  
  		callchain_cursor_advance(&callchain_cursor);
  	}
  
  out:
  	pr_debug2("unknown callsite: %"PRIx64 "\n", sample->ip);
  	return sample->ip;
  }
  
  struct sort_dimension {
  	const char		name[20];
  	sort_fn_t		cmp;
  	struct list_head	list;
  };
  
  static LIST_HEAD(page_alloc_sort_input);
  static LIST_HEAD(page_caller_sort_input);
  
  static struct page_stat *
  __page_stat__findnew_page(struct page_stat *pstat, bool create)
  {
  	struct rb_node **node = &page_live_tree.rb_node;
  	struct rb_node *parent = NULL;
  	struct page_stat *data;
  
  	while (*node) {
  		s64 cmp;
  
  		parent = *node;
  		data = rb_entry(*node, struct page_stat, node);
  
  		cmp = data->page - pstat->page;
  		if (cmp < 0)
  			node = &parent->rb_left;
  		else if (cmp > 0)
  			node = &parent->rb_right;
  		else
  			return data;
  	}
  
  	if (!create)
  		return NULL;
  
  	data = zalloc(sizeof(*data));
  	if (data != NULL) {
  		data->page = pstat->page;
  		data->order = pstat->order;
  		data->gfp_flags = pstat->gfp_flags;
  		data->migrate_type = pstat->migrate_type;
  
  		rb_link_node(&data->node, parent, node);
  		rb_insert_color(&data->node, &page_live_tree);
  	}
  
  	return data;
  }
  
  static struct page_stat *page_stat__find_page(struct page_stat *pstat)
  {
  	return __page_stat__findnew_page(pstat, false);
  }
  
  static struct page_stat *page_stat__findnew_page(struct page_stat *pstat)
  {
  	return __page_stat__findnew_page(pstat, true);
  }
  
  static struct page_stat *
  __page_stat__findnew_alloc(struct page_stat *pstat, bool create)
  {
  	struct rb_node **node = &page_alloc_tree.rb_node;
  	struct rb_node *parent = NULL;
  	struct page_stat *data;
  	struct sort_dimension *sort;
  
  	while (*node) {
  		int cmp = 0;
  
  		parent = *node;
  		data = rb_entry(*node, struct page_stat, node);
  
  		list_for_each_entry(sort, &page_alloc_sort_input, list) {
  			cmp = sort->cmp(pstat, data);
  			if (cmp)
  				break;
  		}
  
  		if (cmp < 0)
  			node = &parent->rb_left;
  		else if (cmp > 0)
  			node = &parent->rb_right;
  		else
  			return data;
  	}
  
  	if (!create)
  		return NULL;
  
  	data = zalloc(sizeof(*data));
  	if (data != NULL) {
  		data->page = pstat->page;
  		data->order = pstat->order;
  		data->gfp_flags = pstat->gfp_flags;
  		data->migrate_type = pstat->migrate_type;
  
  		rb_link_node(&data->node, parent, node);
  		rb_insert_color(&data->node, &page_alloc_tree);
  	}
  
  	return data;
  }
  
  static struct page_stat *page_stat__find_alloc(struct page_stat *pstat)
  {
  	return __page_stat__findnew_alloc(pstat, false);
  }
  
  static struct page_stat *page_stat__findnew_alloc(struct page_stat *pstat)
  {
  	return __page_stat__findnew_alloc(pstat, true);
  }
  
  static struct page_stat *
  __page_stat__findnew_caller(struct page_stat *pstat, bool create)
  {
  	struct rb_node **node = &page_caller_tree.rb_node;
  	struct rb_node *parent = NULL;
  	struct page_stat *data;
  	struct sort_dimension *sort;
  
  	while (*node) {
  		int cmp = 0;
  
  		parent = *node;
  		data = rb_entry(*node, struct page_stat, node);
  
  		list_for_each_entry(sort, &page_caller_sort_input, list) {
  			cmp = sort->cmp(pstat, data);
  			if (cmp)
  				break;
  		}
  
  		if (cmp < 0)
  			node = &parent->rb_left;
  		else if (cmp > 0)
  			node = &parent->rb_right;
  		else
  			return data;
  	}
  
  	if (!create)
  		return NULL;
  
  	data = zalloc(sizeof(*data));
  	if (data != NULL) {
  		data->callsite = pstat->callsite;
  		data->order = pstat->order;
  		data->gfp_flags = pstat->gfp_flags;
  		data->migrate_type = pstat->migrate_type;
  
  		rb_link_node(&data->node, parent, node);
  		rb_insert_color(&data->node, &page_caller_tree);
  	}
  
  	return data;
  }
  
  static struct page_stat *page_stat__find_caller(struct page_stat *pstat)
  {
  	return __page_stat__findnew_caller(pstat, false);
  }
  
  static struct page_stat *page_stat__findnew_caller(struct page_stat *pstat)
  {
  	return __page_stat__findnew_caller(pstat, true);
  }
  
  static bool valid_page(u64 pfn_or_page)
  {
  	if (use_pfn && pfn_or_page == -1UL)
  		return false;
  	if (!use_pfn && pfn_or_page == 0)
  		return false;
  	return true;
  }
  
  struct gfp_flag {
  	unsigned int flags;
  	char *compact_str;
  	char *human_readable;
  };
  
  static struct gfp_flag *gfps;
  static int nr_gfps;
  
  static int gfpcmp(const void *a, const void *b)
  {
  	const struct gfp_flag *fa = a;
  	const struct gfp_flag *fb = b;
  
  	return fa->flags - fb->flags;
  }
  
  /* see include/trace/events/mmflags.h */
  static const struct {
  	const char *original;
  	const char *compact;
  } gfp_compact_table[] = {
  	{ "GFP_TRANSHUGE",		"THP" },
  	{ "GFP_TRANSHUGE_LIGHT",	"THL" },
  	{ "GFP_HIGHUSER_MOVABLE",	"HUM" },
  	{ "GFP_HIGHUSER",		"HU" },
  	{ "GFP_USER",			"U" },
  	{ "GFP_KERNEL_ACCOUNT",		"KAC" },
  	{ "GFP_KERNEL",			"K" },
  	{ "GFP_NOFS",			"NF" },
  	{ "GFP_ATOMIC",			"A" },
  	{ "GFP_NOIO",			"NI" },
  	{ "GFP_NOWAIT",			"NW" },
  	{ "GFP_DMA",			"D" },
  	{ "__GFP_HIGHMEM",		"HM" },
  	{ "GFP_DMA32",			"D32" },
  	{ "__GFP_HIGH",			"H" },
  	{ "__GFP_ATOMIC",		"_A" },
  	{ "__GFP_IO",			"I" },
  	{ "__GFP_FS",			"F" },
  	{ "__GFP_COLD",			"CO" },
  	{ "__GFP_NOWARN",		"NWR" },
  	{ "__GFP_RETRY_MAYFAIL",	"R" },
  	{ "__GFP_NOFAIL",		"NF" },
  	{ "__GFP_NORETRY",		"NR" },
  	{ "__GFP_COMP",			"C" },
  	{ "__GFP_ZERO",			"Z" },
  	{ "__GFP_NOMEMALLOC",		"NMA" },
  	{ "__GFP_MEMALLOC",		"MA" },
  	{ "__GFP_HARDWALL",		"HW" },
  	{ "__GFP_THISNODE",		"TN" },
  	{ "__GFP_RECLAIMABLE",		"RC" },
  	{ "__GFP_MOVABLE",		"M" },
  	{ "__GFP_ACCOUNT",		"AC" },
  	{ "__GFP_NOTRACK",		"NT" },
  	{ "__GFP_WRITE",		"WR" },
  	{ "__GFP_RECLAIM",		"R" },
  	{ "__GFP_DIRECT_RECLAIM",	"DR" },
  	{ "__GFP_KSWAPD_RECLAIM",	"KR" },
  };
  
  static size_t max_gfp_len;
  
  static char *compact_gfp_flags(char *gfp_flags)
  {
  	char *orig_flags = strdup(gfp_flags);
  	char *new_flags = NULL;
  	char *str, *pos = NULL;
  	size_t len = 0;
  
  	if (orig_flags == NULL)
  		return NULL;
  
  	str = strtok_r(orig_flags, "|", &pos);
  	while (str) {
  		size_t i;
  		char *new;
  		const char *cpt;
  
  		for (i = 0; i < ARRAY_SIZE(gfp_compact_table); i++) {
  			if (strcmp(gfp_compact_table[i].original, str))
  				continue;
  
  			cpt = gfp_compact_table[i].compact;
  			new = realloc(new_flags, len + strlen(cpt) + 2);
  			if (new == NULL) {
  				free(new_flags);
  				return NULL;
  			}
  
  			new_flags = new;
  
  			if (!len) {
  				strcpy(new_flags, cpt);
  			} else {
  				strcat(new_flags, "|");
  				strcat(new_flags, cpt);
  				len++;
  			}
  
  			len += strlen(cpt);
  		}
  
  		str = strtok_r(NULL, "|", &pos);
  	}
  
  	if (max_gfp_len < len)
  		max_gfp_len = len;
  
  	free(orig_flags);
  	return new_flags;
  }
  
  static char *compact_gfp_string(unsigned long gfp_flags)
  {
  	struct gfp_flag key = {
  		.flags = gfp_flags,
  	};
  	struct gfp_flag *gfp;
  
  	gfp = bsearch(&key, gfps, nr_gfps, sizeof(*gfps), gfpcmp);
  	if (gfp)
  		return gfp->compact_str;
  
  	return NULL;
  }
  
  static int parse_gfp_flags(struct perf_evsel *evsel, struct perf_sample *sample,
  			   unsigned int gfp_flags)
  {
  	struct pevent_record record = {
  		.cpu = sample->cpu,
  		.data = sample->raw_data,
  		.size = sample->raw_size,
  	};
  	struct trace_seq seq;
  	char *str, *pos = NULL;
  
  	if (nr_gfps) {
  		struct gfp_flag key = {
  			.flags = gfp_flags,
  		};
  
  		if (bsearch(&key, gfps, nr_gfps, sizeof(*gfps), gfpcmp))
  			return 0;
  	}
  
  	trace_seq_init(&seq);
  	pevent_event_info(&seq, evsel->tp_format, &record);
  
  	str = strtok_r(seq.buffer, " ", &pos);
  	while (str) {
  		if (!strncmp(str, "gfp_flags=", 10)) {
  			struct gfp_flag *new;
  
  			new = realloc(gfps, (nr_gfps + 1) * sizeof(*gfps));
  			if (new == NULL)
  				return -ENOMEM;
  
  			gfps = new;
  			new += nr_gfps++;
  
  			new->flags = gfp_flags;
  			new->human_readable = strdup(str + 10);
  			new->compact_str = compact_gfp_flags(str + 10);
  			if (!new->human_readable || !new->compact_str)
  				return -ENOMEM;
  
  			qsort(gfps, nr_gfps, sizeof(*gfps), gfpcmp);
  		}
  
  		str = strtok_r(NULL, " ", &pos);
  	}
  
  	trace_seq_destroy(&seq);
  	return 0;
  }
  
  static int perf_evsel__process_page_alloc_event(struct perf_evsel *evsel,
  						struct perf_sample *sample)
  {
  	u64 page;
  	unsigned int order = perf_evsel__intval(evsel, sample, "order");
  	unsigned int gfp_flags = perf_evsel__intval(evsel, sample, "gfp_flags");
  	unsigned int migrate_type = perf_evsel__intval(evsel, sample,
  						       "migratetype");
  	u64 bytes = kmem_page_size << order;
  	u64 callsite;
  	struct page_stat *pstat;
  	struct page_stat this = {
  		.order = order,
  		.gfp_flags = gfp_flags,
  		.migrate_type = migrate_type,
  	};
  
  	if (use_pfn)
  		page = perf_evsel__intval(evsel, sample, "pfn");
  	else
  		page = perf_evsel__intval(evsel, sample, "page");
  
  	nr_page_allocs++;
  	total_page_alloc_bytes += bytes;
  
  	if (!valid_page(page)) {
  		nr_page_fails++;
  		total_page_fail_bytes += bytes;
  
  		return 0;
  	}
  
  	if (parse_gfp_flags(evsel, sample, gfp_flags) < 0)
  		return -1;
  
  	callsite = find_callsite(evsel, sample);
  
  	/*
  	 * This is to find the current page (with correct gfp flags and
  	 * migrate type) at free event.
  	 */
  	this.page = page;
  	pstat = page_stat__findnew_page(&this);
  	if (pstat == NULL)
  		return -ENOMEM;
  
  	pstat->nr_alloc++;
  	pstat->alloc_bytes += bytes;
  	pstat->callsite = callsite;
  
  	if (!live_page) {
  		pstat = page_stat__findnew_alloc(&this);
  		if (pstat == NULL)
  			return -ENOMEM;
  
  		pstat->nr_alloc++;
  		pstat->alloc_bytes += bytes;
  		pstat->callsite = callsite;
  	}
  
  	this.callsite = callsite;
  	pstat = page_stat__findnew_caller(&this);
  	if (pstat == NULL)
  		return -ENOMEM;
  
  	pstat->nr_alloc++;
  	pstat->alloc_bytes += bytes;
  
  	order_stats[order][migrate_type]++;
  
  	return 0;
  }
  
  static int perf_evsel__process_page_free_event(struct perf_evsel *evsel,
  						struct perf_sample *sample)
  {
  	u64 page;
  	unsigned int order = perf_evsel__intval(evsel, sample, "order");
  	u64 bytes = kmem_page_size << order;
  	struct page_stat *pstat;
  	struct page_stat this = {
  		.order = order,
  	};
  
  	if (use_pfn)
  		page = perf_evsel__intval(evsel, sample, "pfn");
  	else
  		page = perf_evsel__intval(evsel, sample, "page");
  
  	nr_page_frees++;
  	total_page_free_bytes += bytes;
  
  	this.page = page;
  	pstat = page_stat__find_page(&this);
  	if (pstat == NULL) {
  		pr_debug2("missing free at page %"PRIx64" (order: %d)\n",
  			  page, order);
  
  		nr_page_nomatch++;
  		total_page_nomatch_bytes += bytes;
  
  		return 0;
  	}
  
  	this.gfp_flags = pstat->gfp_flags;
  	this.migrate_type = pstat->migrate_type;
  	this.callsite = pstat->callsite;
  
  	rb_erase(&pstat->node, &page_live_tree);
  	free(pstat);
  
  	if (live_page) {
  		order_stats[this.order][this.migrate_type]--;
  	} else {
  		pstat = page_stat__find_alloc(&this);
  		if (pstat == NULL)
  			return -ENOMEM;
  
  		pstat->nr_free++;
  		pstat->free_bytes += bytes;
  	}
  
  	pstat = page_stat__find_caller(&this);
  	if (pstat == NULL)
  		return -ENOENT;
  
  	pstat->nr_free++;
  	pstat->free_bytes += bytes;
  
  	if (live_page) {
  		pstat->nr_alloc--;
  		pstat->alloc_bytes -= bytes;
  
  		if (pstat->nr_alloc == 0) {
  			rb_erase(&pstat->node, &page_caller_tree);
  			free(pstat);
  		}
  	}
  
  	return 0;
  }
  
  static bool perf_kmem__skip_sample(struct perf_sample *sample)
  {
  	/* skip sample based on time? */
  	if (perf_time__skip_sample(&ptime, sample->time))
  		return true;
  
  	return false;
  }
  
  typedef int (*tracepoint_handler)(struct perf_evsel *evsel,
  				  struct perf_sample *sample);
  
  static int process_sample_event(struct perf_tool *tool __maybe_unused,
  				union perf_event *event,
  				struct perf_sample *sample,
  				struct perf_evsel *evsel,
  				struct machine *machine)
  {
  	int err = 0;
  	struct thread *thread = machine__findnew_thread(machine, sample->pid,
  							sample->tid);
  
  	if (thread == NULL) {
  		pr_debug("problem processing %d event, skipping it.\n",
  			 event->header.type);
  		return -1;
  	}
  
  	if (perf_kmem__skip_sample(sample))
  		return 0;
  
  	dump_printf(" ... thread: %s:%d\n", thread__comm_str(thread), thread->tid);
  
  	if (evsel->handler != NULL) {
  		tracepoint_handler f = evsel->handler;
  		err = f(evsel, sample);
  	}
  
  	thread__put(thread);
  
  	return err;
  }
  
  static struct perf_tool perf_kmem = {
  	.sample		 = process_sample_event,
  	.comm		 = perf_event__process_comm,
  	.mmap		 = perf_event__process_mmap,
  	.mmap2		 = perf_event__process_mmap2,
  	.namespaces	 = perf_event__process_namespaces,
  	.ordered_events	 = true,
  };
  
  static double fragmentation(unsigned long n_req, unsigned long n_alloc)
  {
  	if (n_alloc == 0)
  		return 0.0;
  	else
  		return 100.0 - (100.0 * n_req / n_alloc);
  }
  
  static void __print_slab_result(struct rb_root *root,
  				struct perf_session *session,
  				int n_lines, int is_caller)
  {
  	struct rb_node *next;
  	struct machine *machine = &session->machines.host;
  
  	printf("%.105s\n", graph_dotted_line);
  	printf(" %-34s |",  is_caller ? "Callsite": "Alloc Ptr");
  	printf(" Total_alloc/Per | Total_req/Per   | Hit      | Ping-pong | Frag\n");
  	printf("%.105s\n", graph_dotted_line);
  
  	next = rb_first(root);
  
  	while (next && n_lines--) {
  		struct alloc_stat *data = rb_entry(next, struct alloc_stat,
  						   node);
  		struct symbol *sym = NULL;
  		struct map *map;
  		char buf[BUFSIZ];
  		u64 addr;
  
  		if (is_caller) {
  			addr = data->call_site;
  			if (!raw_ip)
  				sym = machine__find_kernel_function(machine, addr, &map);
  		} else
  			addr = data->ptr;
  
  		if (sym != NULL)
  			snprintf(buf, sizeof(buf), "%s+%" PRIx64 "", sym->name,
  				 addr - map->unmap_ip(map, sym->start));
  		else
  			snprintf(buf, sizeof(buf), "%#" PRIx64 "", addr);
  		printf(" %-34s |", buf);
  
  		printf(" %9llu/%-5lu | %9llu/%-5lu | %8lu | %9lu | %6.3f%%\n",
  		       (unsigned long long)data->bytes_alloc,
  		       (unsigned long)data->bytes_alloc / data->hit,
  		       (unsigned long long)data->bytes_req,
  		       (unsigned long)data->bytes_req / data->hit,
  		       (unsigned long)data->hit,
  		       (unsigned long)data->pingpong,
  		       fragmentation(data->bytes_req, data->bytes_alloc));
  
  		next = rb_next(next);
  	}
  
  	if (n_lines == -1)
  		printf(" ...                                | ...             | ...             | ...      | ...       | ...   \n");
  
  	printf("%.105s\n", graph_dotted_line);
  }
  
  static const char * const migrate_type_str[] = {
  	"UNMOVABL",
  	"RECLAIM",
  	"MOVABLE",
  	"RESERVED",
  	"CMA/ISLT",
  	"UNKNOWN",
  };
  
  static void __print_page_alloc_result(struct perf_session *session, int n_lines)
  {
  	struct rb_node *next = rb_first(&page_alloc_sorted);
  	struct machine *machine = &session->machines.host;
  	const char *format;
  	int gfp_len = max(strlen("GFP flags"), max_gfp_len);
  
  	printf("\n%.105s\n", graph_dotted_line);
  	printf(" %-16s | %5s alloc (KB) | Hits      | Order | Mig.type | %-*s | Callsite\n",
  	       use_pfn ? "PFN" : "Page", live_page ? "Live" : "Total",
  	       gfp_len, "GFP flags");
  	printf("%.105s\n", graph_dotted_line);
  
  	if (use_pfn)
  		format = " %16llu | %'16llu | %'9d | %5d | %8s | %-*s | %s\n";
  	else
  		format = " %016llx | %'16llu | %'9d | %5d | %8s | %-*s | %s\n";
  
  	while (next && n_lines--) {
  		struct page_stat *data;
  		struct symbol *sym;
  		struct map *map;
  		char buf[32];
  		char *caller = buf;
  
  		data = rb_entry(next, struct page_stat, node);
  		sym = machine__find_kernel_function(machine, data->callsite, &map);
  		if (sym)
  			caller = sym->name;
  		else
  			scnprintf(buf, sizeof(buf), "%"PRIx64, data->callsite);
  
  		printf(format, (unsigned long long)data->page,
  		       (unsigned long long)data->alloc_bytes / 1024,
  		       data->nr_alloc, data->order,
  		       migrate_type_str[data->migrate_type],
  		       gfp_len, compact_gfp_string(data->gfp_flags), caller);
  
  		next = rb_next(next);
  	}
  
  	if (n_lines == -1) {
  		printf(" ...              | ...              | ...       | ...   | ...      | %-*s | ...\n",
  		       gfp_len, "...");
  	}
  
  	printf("%.105s\n", graph_dotted_line);
  }
  
  static void __print_page_caller_result(struct perf_session *session, int n_lines)
  {
  	struct rb_node *next = rb_first(&page_caller_sorted);
  	struct machine *machine = &session->machines.host;
  	int gfp_len = max(strlen("GFP flags"), max_gfp_len);
  
  	printf("\n%.105s\n", graph_dotted_line);
  	printf(" %5s alloc (KB) | Hits      | Order | Mig.type | %-*s | Callsite\n",
  	       live_page ? "Live" : "Total", gfp_len, "GFP flags");
  	printf("%.105s\n", graph_dotted_line);
  
  	while (next && n_lines--) {
  		struct page_stat *data;
  		struct symbol *sym;
  		struct map *map;
  		char buf[32];
  		char *caller = buf;
  
  		data = rb_entry(next, struct page_stat, node);
  		sym = machine__find_kernel_function(machine, data->callsite, &map);
  		if (sym)
  			caller = sym->name;
  		else
  			scnprintf(buf, sizeof(buf), "%"PRIx64, data->callsite);
  
  		printf(" %'16llu | %'9d | %5d | %8s | %-*s | %s\n",
  		       (unsigned long long)data->alloc_bytes / 1024,
  		       data->nr_alloc, data->order,
  		       migrate_type_str[data->migrate_type],
  		       gfp_len, compact_gfp_string(data->gfp_flags), caller);
  
  		next = rb_next(next);
  	}
  
  	if (n_lines == -1) {
  		printf(" ...              | ...       | ...   | ...      | %-*s | ...\n",
  		       gfp_len, "...");
  	}
  
  	printf("%.105s\n", graph_dotted_line);
  }
  
  static void print_gfp_flags(void)
  {
  	int i;
  
  	printf("#\n");
  	printf("# GFP flags\n");
  	printf("# ---------\n");
  	for (i = 0; i < nr_gfps; i++) {
  		printf("# %08x: %*s: %s\n", gfps[i].flags,
  		       (int) max_gfp_len, gfps[i].compact_str,
  		       gfps[i].human_readable);
  	}
  }
  
  static void print_slab_summary(void)
  {
  	printf("\nSUMMARY (SLAB allocator)");
  	printf("\n========================\n");
  	printf("Total bytes requested: %'lu\n", total_requested);
  	printf("Total bytes allocated: %'lu\n", total_allocated);
  	printf("Total bytes freed:     %'lu\n", total_freed);
  	if (total_allocated > total_freed) {
  		printf("Net total bytes allocated: %'lu\n",
  		total_allocated - total_freed);
  	}
  	printf("Total bytes wasted on internal fragmentation: %'lu\n",
  	       total_allocated - total_requested);
  	printf("Internal fragmentation: %f%%\n",
  	       fragmentation(total_requested, total_allocated));
  	printf("Cross CPU allocations: %'lu/%'lu\n", nr_cross_allocs, nr_allocs);
  }
  
  static void print_page_summary(void)
  {
  	int o, m;
  	u64 nr_alloc_freed = nr_page_frees - nr_page_nomatch;
  	u64 total_alloc_freed_bytes = total_page_free_bytes - total_page_nomatch_bytes;
  
  	printf("\nSUMMARY (page allocator)");
  	printf("\n========================\n");
  	printf("%-30s: %'16lu   [ %'16"PRIu64" KB ]\n", "Total allocation requests",
  	       nr_page_allocs, total_page_alloc_bytes / 1024);
  	printf("%-30s: %'16lu   [ %'16"PRIu64" KB ]\n", "Total free requests",
  	       nr_page_frees, total_page_free_bytes / 1024);
  	printf("\n");
  
  	printf("%-30s: %'16"PRIu64"   [ %'16"PRIu64" KB ]\n", "Total alloc+freed requests",
  	       nr_alloc_freed, (total_alloc_freed_bytes) / 1024);
  	printf("%-30s: %'16"PRIu64"   [ %'16"PRIu64" KB ]\n", "Total alloc-only requests",
  	       nr_page_allocs - nr_alloc_freed,
  	       (total_page_alloc_bytes - total_alloc_freed_bytes) / 1024);
  	printf("%-30s: %'16lu   [ %'16"PRIu64" KB ]\n", "Total free-only requests",
  	       nr_page_nomatch, total_page_nomatch_bytes / 1024);
  	printf("\n");
  
  	printf("%-30s: %'16lu   [ %'16"PRIu64" KB ]\n", "Total allocation failures",
  	       nr_page_fails, total_page_fail_bytes / 1024);
  	printf("\n");
  
  	printf("%5s  %12s  %12s  %12s  %12s  %12s\n", "Order",  "Unmovable",
  	       "Reclaimable", "Movable", "Reserved", "CMA/Isolated");
  	printf("%.5s  %.12s  %.12s  %.12s  %.12s  %.12s\n", graph_dotted_line,
  	       graph_dotted_line, graph_dotted_line, graph_dotted_line,
  	       graph_dotted_line, graph_dotted_line);
  
  	for (o = 0; o < MAX_PAGE_ORDER; o++) {
  		printf("%5d", o);
  		for (m = 0; m < MAX_MIGRATE_TYPES - 1; m++) {
  			if (order_stats[o][m])
  				printf("  %'12d", order_stats[o][m]);
  			else
  				printf("  %12c", '.');
  		}
  		printf("\n");
  	}
  }
  
  static void print_slab_result(struct perf_session *session)
  {
  	if (caller_flag)
  		__print_slab_result(&root_caller_sorted, session, caller_lines, 1);
  	if (alloc_flag)
  		__print_slab_result(&root_alloc_sorted, session, alloc_lines, 0);
  	print_slab_summary();
  }
  
  static void print_page_result(struct perf_session *session)
  {
  	if (caller_flag || alloc_flag)
  		print_gfp_flags();
  	if (caller_flag)
  		__print_page_caller_result(session, caller_lines);
  	if (alloc_flag)
  		__print_page_alloc_result(session, alloc_lines);
  	print_page_summary();
  }
  
  static void print_result(struct perf_session *session)
  {
  	if (kmem_slab)
  		print_slab_result(session);
  	if (kmem_page)
  		print_page_result(session);
  }
  
  static LIST_HEAD(slab_caller_sort);
  static LIST_HEAD(slab_alloc_sort);
  static LIST_HEAD(page_caller_sort);
  static LIST_HEAD(page_alloc_sort);
  
  static void sort_slab_insert(struct rb_root *root, struct alloc_stat *data,
  			     struct list_head *sort_list)
  {
  	struct rb_node **new = &(root->rb_node);
  	struct rb_node *parent = NULL;
  	struct sort_dimension *sort;
  
  	while (*new) {
  		struct alloc_stat *this;
  		int cmp = 0;
  
  		this = rb_entry(*new, struct alloc_stat, node);
  		parent = *new;
  
  		list_for_each_entry(sort, sort_list, list) {
  			cmp = sort->cmp(data, this);
  			if (cmp)
  				break;
  		}
  
  		if (cmp > 0)
  			new = &((*new)->rb_left);
  		else
  			new = &((*new)->rb_right);
  	}
  
  	rb_link_node(&data->node, parent, new);
  	rb_insert_color(&data->node, root);
  }
  
  static void __sort_slab_result(struct rb_root *root, struct rb_root *root_sorted,
  			       struct list_head *sort_list)
  {
  	struct rb_node *node;
  	struct alloc_stat *data;
  
  	for (;;) {
  		node = rb_first(root);
  		if (!node)
  			break;
  
  		rb_erase(node, root);
  		data = rb_entry(node, struct alloc_stat, node);
  		sort_slab_insert(root_sorted, data, sort_list);
  	}
  }
  
  static void sort_page_insert(struct rb_root *root, struct page_stat *data,
  			     struct list_head *sort_list)
  {
  	struct rb_node **new = &root->rb_node;
  	struct rb_node *parent = NULL;
  	struct sort_dimension *sort;
  
  	while (*new) {
  		struct page_stat *this;
  		int cmp = 0;
  
  		this = rb_entry(*new, struct page_stat, node);
  		parent = *new;
  
  		list_for_each_entry(sort, sort_list, list) {
  			cmp = sort->cmp(data, this);
  			if (cmp)
  				break;
  		}
  
  		if (cmp > 0)
  			new = &parent->rb_left;
  		else
  			new = &parent->rb_right;
  	}
  
  	rb_link_node(&data->node, parent, new);
  	rb_insert_color(&data->node, root);
  }
  
  static void __sort_page_result(struct rb_root *root, struct rb_root *root_sorted,
  			       struct list_head *sort_list)
  {
  	struct rb_node *node;
  	struct page_stat *data;
  
  	for (;;) {
  		node = rb_first(root);
  		if (!node)
  			break;
  
  		rb_erase(node, root);
  		data = rb_entry(node, struct page_stat, node);
  		sort_page_insert(root_sorted, data, sort_list);
  	}
  }
  
  static void sort_result(void)
  {
  	if (kmem_slab) {
  		__sort_slab_result(&root_alloc_stat, &root_alloc_sorted,
  				   &slab_alloc_sort);
  		__sort_slab_result(&root_caller_stat, &root_caller_sorted,
  				   &slab_caller_sort);
  	}
  	if (kmem_page) {
  		if (live_page)
  			__sort_page_result(&page_live_tree, &page_alloc_sorted,
  					   &page_alloc_sort);
  		else
  			__sort_page_result(&page_alloc_tree, &page_alloc_sorted,
  					   &page_alloc_sort);
  
  		__sort_page_result(&page_caller_tree, &page_caller_sorted,
  				   &page_caller_sort);
  	}
  }
  
  static int __cmd_kmem(struct perf_session *session)
  {
  	int err = -EINVAL;
  	struct perf_evsel *evsel;
  	const struct perf_evsel_str_handler kmem_tracepoints[] = {
  		/* slab allocator */
  		{ "kmem:kmalloc",		perf_evsel__process_alloc_event, },
      		{ "kmem:kmem_cache_alloc",	perf_evsel__process_alloc_event, },
  		{ "kmem:kmalloc_node",		perf_evsel__process_alloc_node_event, },
      		{ "kmem:kmem_cache_alloc_node", perf_evsel__process_alloc_node_event, },
  		{ "kmem:kfree",			perf_evsel__process_free_event, },
      		{ "kmem:kmem_cache_free",	perf_evsel__process_free_event, },
  		/* page allocator */
  		{ "kmem:mm_page_alloc",		perf_evsel__process_page_alloc_event, },
  		{ "kmem:mm_page_free",		perf_evsel__process_page_free_event, },
  	};
  
  	if (!perf_session__has_traces(session, "kmem record"))
  		goto out;
  
  	if (perf_session__set_tracepoints_handlers(session, kmem_tracepoints)) {
  		pr_err("Initializing perf session tracepoint handlers failed\n");
  		goto out;
  	}
  
  	evlist__for_each_entry(session->evlist, evsel) {
  		if (!strcmp(perf_evsel__name(evsel), "kmem:mm_page_alloc") &&
  		    perf_evsel__field(evsel, "pfn")) {
  			use_pfn = true;
  			break;
  		}
  	}
  
  	setup_pager();
  	err = perf_session__process_events(session);
  	if (err != 0) {
  		pr_err("error during process events: %d\n", err);
  		goto out;
  	}
  	sort_result();
  	print_result(session);
  out:
  	return err;
  }
  
  /* slab sort keys */
  static int ptr_cmp(void *a, void *b)
  {
  	struct alloc_stat *l = a;
  	struct alloc_stat *r = b;
  
  	if (l->ptr < r->ptr)
  		return -1;
  	else if (l->ptr > r->ptr)
  		return 1;
  	return 0;
  }
  
  static struct sort_dimension ptr_sort_dimension = {
  	.name	= "ptr",
  	.cmp	= ptr_cmp,
  };
  
  static int slab_callsite_cmp(void *a, void *b)
  {
  	struct alloc_stat *l = a;
  	struct alloc_stat *r = b;
  
  	if (l->call_site < r->call_site)
  		return -1;
  	else if (l->call_site > r->call_site)
  		return 1;
  	return 0;
  }
  
  static struct sort_dimension callsite_sort_dimension = {
  	.name	= "callsite",
  	.cmp	= slab_callsite_cmp,
  };
  
  static int hit_cmp(void *a, void *b)
  {
  	struct alloc_stat *l = a;
  	struct alloc_stat *r = b;
  
  	if (l->hit < r->hit)
  		return -1;
  	else if (l->hit > r->hit)
  		return 1;
  	return 0;
  }
  
  static struct sort_dimension hit_sort_dimension = {
  	.name	= "hit",
  	.cmp	= hit_cmp,
  };
  
  static int bytes_cmp(void *a, void *b)
  {
  	struct alloc_stat *l = a;
  	struct alloc_stat *r = b;
  
  	if (l->bytes_alloc < r->bytes_alloc)
  		return -1;
  	else if (l->bytes_alloc > r->bytes_alloc)
  		return 1;
  	return 0;
  }
  
  static struct sort_dimension bytes_sort_dimension = {
  	.name	= "bytes",
  	.cmp	= bytes_cmp,
  };
  
  static int frag_cmp(void *a, void *b)
  {
  	double x, y;
  	struct alloc_stat *l = a;
  	struct alloc_stat *r = b;
  
  	x = fragmentation(l->bytes_req, l->bytes_alloc);
  	y = fragmentation(r->bytes_req, r->bytes_alloc);
  
  	if (x < y)
  		return -1;
  	else if (x > y)
  		return 1;
  	return 0;
  }
  
  static struct sort_dimension frag_sort_dimension = {
  	.name	= "frag",
  	.cmp	= frag_cmp,
  };
  
  static int pingpong_cmp(void *a, void *b)
  {
  	struct alloc_stat *l = a;
  	struct alloc_stat *r = b;
  
  	if (l->pingpong < r->pingpong)
  		return -1;
  	else if (l->pingpong > r->pingpong)
  		return 1;
  	return 0;
  }
  
  static struct sort_dimension pingpong_sort_dimension = {
  	.name	= "pingpong",
  	.cmp	= pingpong_cmp,
  };
  
  /* page sort keys */
  static int page_cmp(void *a, void *b)
  {
  	struct page_stat *l = a;
  	struct page_stat *r = b;
  
  	if (l->page < r->page)
  		return -1;
  	else if (l->page > r->page)
  		return 1;
  	return 0;
  }
  
  static struct sort_dimension page_sort_dimension = {
  	.name	= "page",
  	.cmp	= page_cmp,
  };
  
  static int page_callsite_cmp(void *a, void *b)
  {
  	struct page_stat *l = a;
  	struct page_stat *r = b;
  
  	if (l->callsite < r->callsite)
  		return -1;
  	else if (l->callsite > r->callsite)
  		return 1;
  	return 0;
  }
  
  static struct sort_dimension page_callsite_sort_dimension = {
  	.name	= "callsite",
  	.cmp	= page_callsite_cmp,
  };
  
  static int page_hit_cmp(void *a, void *b)
  {
  	struct page_stat *l = a;
  	struct page_stat *r = b;
  
  	if (l->nr_alloc < r->nr_alloc)
  		return -1;
  	else if (l->nr_alloc > r->nr_alloc)
  		return 1;
  	return 0;
  }
  
  static struct sort_dimension page_hit_sort_dimension = {
  	.name	= "hit",
  	.cmp	= page_hit_cmp,
  };
  
  static int page_bytes_cmp(void *a, void *b)
  {
  	struct page_stat *l = a;
  	struct page_stat *r = b;
  
  	if (l->alloc_bytes < r->alloc_bytes)
  		return -1;
  	else if (l->alloc_bytes > r->alloc_bytes)
  		return 1;
  	return 0;
  }
  
  static struct sort_dimension page_bytes_sort_dimension = {
  	.name	= "bytes",
  	.cmp	= page_bytes_cmp,
  };
  
  static int page_order_cmp(void *a, void *b)
  {
  	struct page_stat *l = a;
  	struct page_stat *r = b;
  
  	if (l->order < r->order)
  		return -1;
  	else if (l->order > r->order)
  		return 1;
  	return 0;
  }
  
  static struct sort_dimension page_order_sort_dimension = {
  	.name	= "order",
  	.cmp	= page_order_cmp,
  };
  
  static int migrate_type_cmp(void *a, void *b)
  {
  	struct page_stat *l = a;
  	struct page_stat *r = b;
  
  	/* for internal use to find free'd page */
  	if (l->migrate_type == -1U)
  		return 0;
  
  	if (l->migrate_type < r->migrate_type)
  		return -1;
  	else if (l->migrate_type > r->migrate_type)
  		return 1;
  	return 0;
  }
  
  static struct sort_dimension migrate_type_sort_dimension = {
  	.name	= "migtype",
  	.cmp	= migrate_type_cmp,
  };
  
  static int gfp_flags_cmp(void *a, void *b)
  {
  	struct page_stat *l = a;
  	struct page_stat *r = b;
  
  	/* for internal use to find free'd page */
  	if (l->gfp_flags == -1U)
  		return 0;
  
  	if (l->gfp_flags < r->gfp_flags)
  		return -1;
  	else if (l->gfp_flags > r->gfp_flags)
  		return 1;
  	return 0;
  }
  
  static struct sort_dimension gfp_flags_sort_dimension = {
  	.name	= "gfp",
  	.cmp	= gfp_flags_cmp,
  };
  
  static struct sort_dimension *slab_sorts[] = {
  	&ptr_sort_dimension,
  	&callsite_sort_dimension,
  	&hit_sort_dimension,
  	&bytes_sort_dimension,
  	&frag_sort_dimension,
  	&pingpong_sort_dimension,
  };
  
  static struct sort_dimension *page_sorts[] = {
  	&page_sort_dimension,
  	&page_callsite_sort_dimension,
  	&page_hit_sort_dimension,
  	&page_bytes_sort_dimension,
  	&page_order_sort_dimension,
  	&migrate_type_sort_dimension,
  	&gfp_flags_sort_dimension,
  };
  
  static int slab_sort_dimension__add(const char *tok, struct list_head *list)
  {
  	struct sort_dimension *sort;
  	int i;
  
  	for (i = 0; i < (int)ARRAY_SIZE(slab_sorts); i++) {
  		if (!strcmp(slab_sorts[i]->name, tok)) {
  			sort = memdup(slab_sorts[i], sizeof(*slab_sorts[i]));
  			if (!sort) {
  				pr_err("%s: memdup failed\n", __func__);
  				return -1;
  			}
  			list_add_tail(&sort->list, list);
  			return 0;
  		}
  	}
  
  	return -1;
  }
  
  static int page_sort_dimension__add(const char *tok, struct list_head *list)
  {
  	struct sort_dimension *sort;
  	int i;
  
  	for (i = 0; i < (int)ARRAY_SIZE(page_sorts); i++) {
  		if (!strcmp(page_sorts[i]->name, tok)) {
  			sort = memdup(page_sorts[i], sizeof(*page_sorts[i]));
  			if (!sort) {
  				pr_err("%s: memdup failed\n", __func__);
  				return -1;
  			}
  			list_add_tail(&sort->list, list);
  			return 0;
  		}
  	}
  
  	return -1;
  }
  
  static int setup_slab_sorting(struct list_head *sort_list, const char *arg)
  {
  	char *tok;
  	char *str = strdup(arg);
  	char *pos = str;
  
  	if (!str) {
  		pr_err("%s: strdup failed\n", __func__);
  		return -1;
  	}
  
  	while (true) {
  		tok = strsep(&pos, ",");
  		if (!tok)
  			break;
  		if (slab_sort_dimension__add(tok, sort_list) < 0) {
  			pr_err("Unknown slab --sort key: '%s'", tok);
  			free(str);
  			return -1;
  		}
  	}
  
  	free(str);
  	return 0;
  }
  
  static int setup_page_sorting(struct list_head *sort_list, const char *arg)
  {
  	char *tok;
  	char *str = strdup(arg);
  	char *pos = str;
  
  	if (!str) {
  		pr_err("%s: strdup failed\n", __func__);
  		return -1;
  	}
  
  	while (true) {
  		tok = strsep(&pos, ",");
  		if (!tok)
  			break;
  		if (page_sort_dimension__add(tok, sort_list) < 0) {
  			pr_err("Unknown page --sort key: '%s'", tok);
  			free(str);
  			return -1;
  		}
  	}
  
  	free(str);
  	return 0;
  }
  
  static int parse_sort_opt(const struct option *opt __maybe_unused,
  			  const char *arg, int unset __maybe_unused)
  {
  	if (!arg)
  		return -1;
  
  	if (kmem_page > kmem_slab ||
  	    (kmem_page == 0 && kmem_slab == 0 && kmem_default == KMEM_PAGE)) {
  		if (caller_flag > alloc_flag)
  			return setup_page_sorting(&page_caller_sort, arg);
  		else
  			return setup_page_sorting(&page_alloc_sort, arg);
  	} else {
  		if (caller_flag > alloc_flag)
  			return setup_slab_sorting(&slab_caller_sort, arg);
  		else
  			return setup_slab_sorting(&slab_alloc_sort, arg);
  	}
  
  	return 0;
  }
  
  static int parse_caller_opt(const struct option *opt __maybe_unused,
  			    const char *arg __maybe_unused,
  			    int unset __maybe_unused)
  {
  	caller_flag = (alloc_flag + 1);
  	return 0;
  }
  
  static int parse_alloc_opt(const struct option *opt __maybe_unused,
  			   const char *arg __maybe_unused,
  			   int unset __maybe_unused)
  {
  	alloc_flag = (caller_flag + 1);
  	return 0;
  }
  
  static int parse_slab_opt(const struct option *opt __maybe_unused,
  			  const char *arg __maybe_unused,
  			  int unset __maybe_unused)
  {
  	kmem_slab = (kmem_page + 1);
  	return 0;
  }
  
  static int parse_page_opt(const struct option *opt __maybe_unused,
  			  const char *arg __maybe_unused,
  			  int unset __maybe_unused)
  {
  	kmem_page = (kmem_slab + 1);
  	return 0;
  }
  
  static int parse_line_opt(const struct option *opt __maybe_unused,
  			  const char *arg, int unset __maybe_unused)
  {
  	int lines;
  
  	if (!arg)
  		return -1;
  
  	lines = strtoul(arg, NULL, 10);
  
  	if (caller_flag > alloc_flag)
  		caller_lines = lines;
  	else
  		alloc_lines = lines;
  
  	return 0;
  }
  
  static int __cmd_record(int argc, const char **argv)
  {
  	const char * const record_args[] = {
  	"record", "-a", "-R", "-c", "1",
  	};
  	const char * const slab_events[] = {
  	"-e", "kmem:kmalloc",
  	"-e", "kmem:kmalloc_node",
  	"-e", "kmem:kfree",
  	"-e", "kmem:kmem_cache_alloc",
  	"-e", "kmem:kmem_cache_alloc_node",
  	"-e", "kmem:kmem_cache_free",
  	};
  	const char * const page_events[] = {
  	"-e", "kmem:mm_page_alloc",
  	"-e", "kmem:mm_page_free",
  	};
  	unsigned int rec_argc, i, j;
  	const char **rec_argv;
  
  	rec_argc = ARRAY_SIZE(record_args) + argc - 1;
  	if (kmem_slab)
  		rec_argc += ARRAY_SIZE(slab_events);
  	if (kmem_page)
  		rec_argc += ARRAY_SIZE(page_events) + 1; /* for -g */
  
  	rec_argv = calloc(rec_argc + 1, sizeof(char *));
  
  	if (rec_argv == NULL)
  		return -ENOMEM;
  
  	for (i = 0; i < ARRAY_SIZE(record_args); i++)
  		rec_argv[i] = strdup(record_args[i]);
  
  	if (kmem_slab) {
  		for (j = 0; j < ARRAY_SIZE(slab_events); j++, i++)
  			rec_argv[i] = strdup(slab_events[j]);
  	}
  	if (kmem_page) {
  		rec_argv[i++] = strdup("-g");
  
  		for (j = 0; j < ARRAY_SIZE(page_events); j++, i++)
  			rec_argv[i] = strdup(page_events[j]);
  	}
  
  	for (j = 1; j < (unsigned int)argc; j++, i++)
  		rec_argv[i] = argv[j];
  
  	return cmd_record(i, rec_argv);
  }
  
  static int kmem_config(const char *var, const char *value, void *cb __maybe_unused)
  {
  	if (!strcmp(var, "kmem.default")) {
  		if (!strcmp(value, "slab"))
  			kmem_default = KMEM_SLAB;
  		else if (!strcmp(value, "page"))
  			kmem_default = KMEM_PAGE;
  		else
  			pr_err("invalid default value ('slab' or 'page' required): %s\n",
  			       value);
  		return 0;
  	}
  
  	return 0;
  }
  
  int cmd_kmem(int argc, const char **argv)
  {
  	const char * const default_slab_sort = "frag,hit,bytes";
  	const char * const default_page_sort = "bytes,hit";
  	struct perf_data_file file = {
  		.mode = PERF_DATA_MODE_READ,
  	};
  	const struct option kmem_options[] = {
  	OPT_STRING('i', "input", &input_name, "file", "input file name"),
  	OPT_INCR('v', "verbose", &verbose,
  		    "be more verbose (show symbol address, etc)"),
  	OPT_CALLBACK_NOOPT(0, "caller", NULL, NULL,
  			   "show per-callsite statistics", parse_caller_opt),
  	OPT_CALLBACK_NOOPT(0, "alloc", NULL, NULL,
  			   "show per-allocation statistics", parse_alloc_opt),
  	OPT_CALLBACK('s', "sort", NULL, "key[,key2...]",
  		     "sort by keys: ptr, callsite, bytes, hit, pingpong, frag, "
  		     "page, order, migtype, gfp", parse_sort_opt),
  	OPT_CALLBACK('l', "line", NULL, "num", "show n lines", parse_line_opt),
  	OPT_BOOLEAN(0, "raw-ip", &raw_ip, "show raw ip instead of symbol"),
  	OPT_BOOLEAN('f', "force", &file.force, "don't complain, do it"),
  	OPT_CALLBACK_NOOPT(0, "slab", NULL, NULL, "Analyze slab allocator",
  			   parse_slab_opt),
  	OPT_CALLBACK_NOOPT(0, "page", NULL, NULL, "Analyze page allocator",
  			   parse_page_opt),
  	OPT_BOOLEAN(0, "live", &live_page, "Show live page stat"),
  	OPT_STRING(0, "time", &time_str, "str",
  		   "Time span of interest (start,stop)"),
  	OPT_END()
  	};
  	const char *const kmem_subcommands[] = { "record", "stat", NULL };
  	const char *kmem_usage[] = {
  		NULL,
  		NULL
  	};
  	struct perf_session *session;
  	const char errmsg[] = "No %s allocation events found.  Have you run 'perf kmem record --%s'?\n";
  	int ret = perf_config(kmem_config, NULL);
  
  	if (ret)
  		return ret;
  
  	argc = parse_options_subcommand(argc, argv, kmem_options,
  					kmem_subcommands, kmem_usage, 0);
  
  	if (!argc)
  		usage_with_options(kmem_usage, kmem_options);
  
  	if (kmem_slab == 0 && kmem_page == 0) {
  		if (kmem_default == KMEM_SLAB)
  			kmem_slab = 1;
  		else
  			kmem_page = 1;
  	}
  
  	if (!strncmp(argv[0], "rec", 3)) {
  		symbol__init(NULL);
  		return __cmd_record(argc, argv);
  	}
  
  	file.path = input_name;
  
  	kmem_session = session = perf_session__new(&file, false, &perf_kmem);
  	if (session == NULL)
  		return -1;
  
  	ret = -1;
  
  	if (kmem_slab) {
  		if (!perf_evlist__find_tracepoint_by_name(session->evlist,
  							  "kmem:kmalloc")) {
  			pr_err(errmsg, "slab", "slab");
  			goto out_delete;
  		}
  	}
  
  	if (kmem_page) {
  		struct perf_evsel *evsel;
  
  		evsel = perf_evlist__find_tracepoint_by_name(session->evlist,
  							     "kmem:mm_page_alloc");
  		if (evsel == NULL) {
  			pr_err(errmsg, "page", "page");
  			goto out_delete;
  		}
  
  		kmem_page_size = pevent_get_page_size(evsel->tp_format->pevent);
  		symbol_conf.use_callchain = true;
  	}
  
  	symbol__init(&session->header.env);
  
  	if (perf_time__parse_str(&ptime, time_str) != 0) {
  		pr_err("Invalid time string\n");
  		return -EINVAL;
  	}
  
  	if (!strcmp(argv[0], "stat")) {
  		setlocale(LC_ALL, "");
  
  		if (cpu__setup_cpunode_map())
  			goto out_delete;
  
  		if (list_empty(&slab_caller_sort))
  			setup_slab_sorting(&slab_caller_sort, default_slab_sort);
  		if (list_empty(&slab_alloc_sort))
  			setup_slab_sorting(&slab_alloc_sort, default_slab_sort);
  		if (list_empty(&page_caller_sort))
  			setup_page_sorting(&page_caller_sort, default_page_sort);
  		if (list_empty(&page_alloc_sort))
  			setup_page_sorting(&page_alloc_sort, default_page_sort);
  
  		if (kmem_page) {
  			setup_page_sorting(&page_alloc_sort_input,
  					   "page,order,migtype,gfp");
  			setup_page_sorting(&page_caller_sort_input,
  					   "callsite,order,migtype,gfp");
  		}
  		ret = __cmd_kmem(session);
  	} else
  		usage_with_options(kmem_usage, kmem_options);
  
  out_delete:
  	perf_session__delete(session);
  
  	return ret;
  }
  
  